A filing, which was revealed today, showed that Hyundai agreed to general terms of a settlement earlier this month. No financial terms have been disclosed, so it is unclear what Hyundai will have to pay under the settlement.

The proposed settlement gives owners of Hyundai models with misstated fuel economy ratings the choice to either continue accepting money through the debit card plan (which offers periodic payments to a credit card) or receive a lump sum settlement payout.

Payout amounts will depend on the difference in fuel economy from the actual figure to the overstated figure. Those with previously rated 40 MPG models -- like the Accent, Elantra, Veloster and Sonata Hybrid -- are expected to get a larger payout than those with under 40 MPG.

Hyundai said it had set aside about $225 million for its owner compensation plans.

Kia was also busted for overstating fuel economy ratings for some of its models, but the automaker was not a part of Hyundai's settlement. However, Kia was invited to join the settlement and is currently reviewing the terms.

Back in December 2011, Consumer Watchdog called on the EPA to investigate Hyundai over its fuel economy claims. Hyundai claimed that its Elantra achieved 29 MPG in the city and 40 MPG on highway. However, the organization received a higher-than-usual number of complaints that real-world mileage was in the mid-20 mpg range.

The EPA investigated Hyundai for misleading mileage claims and found that the fuel economy estimates of most of its 2012-2013 models were overstated. It made the same conclusion for Kia, and both automakers said they would lower the fuel economy estimates on the majority of their 2012 to 2013 models.

Hyundai and Kia admitted to overstating the estimated fuel economy on window stickers of about 900,000 vehicles sold in the U.S. since late 2010. Some of the MPG window stickers that will required include the Hyundai Accent and the Kia Soul ECO. The Accent had its 30/40/33 (city/highway/combined) rating drop to 28/37/31. The Kia Soul ECO saw the biggest drop of any affected model going from 27/35/30 to 24/29/26.

Kia said it has set aside about $187 million for its owner compensation plans.

Real-world reports mean nothing if you only hear about the guys posting on forums (self selected anomalous results) using flawed measurement methods.

When someone has an understanding of statistics, they get results like this:http://www.bobistheoilguy.com/forums/ubbthreads.ph...Even with 10 tanks of measurements, the ~2% difference he found was deemed statistically insignificant (p=0.56, far from the general standard of p<0.05).